Preoperative predictors of surgical approach for partial nephrectomy

Introduction: To evaluate preoperative parameters of patients undergoing partial nephrectomy to determine variables that impact selection of operative approach. Materials and methods: The charts of 229 consecutive patients undergoing partial nephrectomy were reviewed. Clinical data points and associated axial imaging were evaluated to determine factors which contributed to selection of an open (versus laparoscopic) operation. Results: A total of 140 men and 89 women with a mean age of 57 years, body mass index (BMI) of 31, and glomerular filtration rate (GFR) of 82 mL/min/1.73 m2 were included. Twenty-three percent of patients had prior abdominal surgery and 7% had a history of contralateral renal cell carcinoma (RCC). The mean tumor size was 3.4 cm (range, 0.7-11) with 23% of lesions being endophytic, 38% involving the collecting system, and 29% being hilar. Thirty-four patients (15%) had multifocal lesions. Overall, 130 patients underwent an open partial nephrectomy (OPN) and 99 a laparoscopic partial nephrectomy (LPN). On univariate analysis, preoperative GFR (p = 0.05), a history of contralateral RCC surgery (p = 0.02), tumor size (p = 0.04), renal sinus/collecting system involvement (p = 0.001), renal hilar location (p = 0.001), tumor multifocality (p = 0.004), surgeon laparoscopic case volume of < 25 cases (p = 0.03), and lack of fellowship laparoscopic training (p = 0.02) all were associated with an open surgical approach. In a logistic regression model incorporating these eight variables, only renal hilar location (OR 2.63, 95% CI 1.17-5.88, p = 0.02) remained significantly associated with OPN. Conclusions: Many parameters including increasing BMI, preoperative GFR, prior abdominal surgery, endophytic tumor location, and renal sinus/collecting system involvement do not necessarily preclude a minimally invasive partial nephrectomy. In our experience, renal hilar tumors were over 2.5 fold more likely to be managed by OPN owing to the complexity of resection.